Didn't think much of this till a very similar number did the same thing two days later: short but unintelligible (like digital break up or static) message. Made me call back, almost, til I realised I hadn't given this number out to anyone for a LONG time and have registered with 'do not call' - meaning cold calls from businesses shouldn't be getting through. Anyone else having calls from these numbers? Is it maybe a charity? For reasons that fail me they are exempt from 'do not call'!